Transanal excision of rectal neoplasms has until recently been essentially limited to tumors of the low rectum. However, transanal endoscopic microsurgery (TEM) allowed access to higher rectal tumors through the use of specialized equipment in order to avoid unnecessary proctectomy (Buess G, Theiss R, Gunther M, Hutterer F, Pichlmaier H. Transanal endoscopic microsurgery. Leber Magen Darm 1985; 15:271-279; Buess G, Kipfmuller K, Hack D, Grussner R, Heintz A, Junginger T. Technique of transanal endoscopic microsurgery. Surg Endosc 1988; 2:71-75; Buess G. Review: transanal endoscopic microsurgery (TEM). J R Coll Surg Edinb 1993; 38:239-245).
A more recent advancement hybridizing the concept of TEM with single-incision laparoscopy has led to the creation of transanal minimally invasive surgery (TAMIS) (Atallah S, Albert M, Larach S. Transanal minimally invasive surgery: a giant leap forward. Surg Endosc 2010; 24:2200-2205). This innovative approach is seeing increasing popularity as a safe, feasible and cost-effective alternative to TEM, providing the benefits at reduced cost with a possibly shorter learning curve (Walensi M, Kaser S A, Theodorou P, Bassotti G, Cathomas G, Maurer C A. Transanal endoscopic microsurgery (TEM) facilitated by video-assistance and anal insertion of a single-incision laparoscopic surgery (SILS®)-port: preliminary experience. World J Surg 2014; 38:505-511; Khoo R E. Transanal excision of a rectal adenoma using single-access laparoscopic port. Dis Colon Rectum 2010; 53:1078-1079; Slack T, Wong S, Muhlmann M. Transanal minimally invasive surgery: an initial experience. ANZ J Surg 2014; 84:177-180; Lee T G, Lee S J. Transanal single-port microsurgery for rectal tumors: minimal invasive surgery under spinal anesthesia. Surg Endosc 2014; 28:271-280).
TAMIS is generally easier to set up, and provides a viewing quality comparable to traditional laparoscopy. Additionally, single-incision laparoscopic ports allow greater instrument maneuverability, and have been shown to cause less anorectal trauma (Walensi M, Kaser S A, Theodorou P, Bassotti G, Cathomas G, Maurer C A. Transanal endoscopic microsurgery (TEM) facilitated by video-assistance and anal insertion of a single-incision laparoscopic surgery (SILS®)-port: preliminary experience. World J Surg 2014; 38:505-511; Slack T, Wong S, Muhlmann M. Transanal minimally invasive surgery: an initial experience. ANZ J Surg 2014; 84:177-180; Barendse R M, Doornebosch P G, Bemelman W A, Fockens P, Dekker E, de Graaf E J. Transanal employment of single access ports is feasible for rectal surgery. Ann Surg 2012; 256:1030-1033; Hayashi S, Takayama T, Yamagata M, Matsuda M, Masuda H. Single-incision laparoscopic surgery used to perform transanal endoscopic microsurgery (SILSTEM) for T1 rectal cancer under spinal anesthesia: report of a case. Surg Today 2013; 43:325-328; Canda A E, Terzi C, Sagol O, Sarioglu S, Obuz F, Fuzun M. Transanal single-port access microsurgery (TSPAM). Surg Laparosc Endosc Percutan Tech 2012; 22:349-353).
Despite its multiple advantages over traditional transanal excision techniques, TAMIS does have its limitations. Single port procedures can be expensive, and have an inherent tendency for instrument clash (Sehgal R, Cahill R A. Advanced laparoscopic surgery for colorectal disease: NOTES/NOSE or single port? Best Pract Res Clin Gastroenterol. 2014; 28:81-96). Rectal insufflation can be lost through the trocar seals when torque forces on the instruments are extreme, or it can also be lost passively into the proximal bowel (Atallah S B, Albert M R, deBeche-Adams T H, Larach S W. Robotic transanal minimally invasive surgery in a cadaveric model. Tech Coloproctol 2011; 15:461-464). Additionally, the cost-effectiveness of TAMIS may be limited by the need for an assistant surgeon to manage the camera (Barendse R M, Doornebosch P G, Bemelman W A, Fockens P, Dekker E, de Graaf E J. Transanal employment of single access ports is feasible for rectal surgery. Ann Surg 2012; 256:1030-1033; Rimonda R, Arezzo A, Arolfo S, Salvai A, Morino M. TransAnal Minimally Invasive Surgery (TAMIS) with SILS™ port versus Transanal Endoscopic Microsurgery (TEM): a comparative experimental study. Surg Endosc 2013; 27:3762-3768). TAMIS has also been reported to have longer operative times than TEM (; Rimonda R, Arezzo A, Arolfo S, Salvai A, Morino M. TransAnal Minimally Invasive Surgery (TAMIS) with SILS™ port versus Transanal Endoscopic Microsurgery (TEM): a comparative experimental study. Surg Endosc 2013; 27:3762-3768).
Colon and rectal surgeons have commonly encountered some major time-consuming and technical obstacles to performing safe and efficient TAMIS procedures such as fluctuation of pneumorectum as insufflation gas escapes proximally into the bowel, causing repeated collapse of the rectal lumen as well as dense smoke created from electrocautery devices obscuring the visual field.
The instant invention alleviates the above obstacles encountered during TAMIS procedures and in addition can be used for any sort of endoscopic procedure to ensure a clear visual field during the procedure.